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Multi-Way Conventional loudspeakers with crossovers

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Old 9th October 2010, 11:09 PM   #11
DQ828 is offline DQ828  Australia
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Quote:
Originally Posted by Helmuth View Post
I ask my self how do you choose your woofer for a open baffle.

Speakers for open baffle prefer to have high qes and qts. value's around 0,5-1 and low Fs is a good indication.

A good high efficient woofer is a eminence kilomax. Or a beyma sn118.
http://profesional.beyma.com/pdf/SM-118%20NE.pdf

They are too large for my design I want to have a maximum size base driver of 12"
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Old 10th October 2010, 07:13 AM   #12
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Quote:
Originally Posted by Helmuth View Post
I ask my self how do you choose your woofer for a open baffle.

Speakers for open baffle prefer to have high qes and qts. value's around 0,5-1 and low Fs is a good indication.

A good high efficient woofer is a eminence kilomax. Or a beyma sn118.
http://profesional.beyma.com/pdf/SM-118%20NE.pdf

I just had a look at the drivers Linkwitz uses & his bass drivers for the Orion have a Qts of 0.17?
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Old 10th October 2010, 07:51 AM   #13
Helmuth is offline Helmuth  Netherlands
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Quote:
Originally Posted by DQ828 View Post
Hi Helmut


What do you think about the baffle shape & the obscuring of the speaker?
Click the image to open in full size.
I have the experience that a flat baffle isn't perfect.

It shout have sloping side's( like you did) so the reflections on the baffle go side ways and not go cross the front radiated sound. Your design is nice to see but I would not make it deep is you did in this drawing. I think it has to be flat with sloping side's. To control the reflections on the baffle.
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Old 10th October 2010, 07:58 AM   #14
Helmuth is offline Helmuth  Netherlands
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Quote:
Originally Posted by DQ828 View Post
I just had a look at the drivers Linkwitz uses & his bass drivers for the Orion have a Qts of 0.17?
Then I have to simulate that one. With that Q it shout have very low Fs and big x-max and equaliser.

I know linkwitz uses a formula that calculates a driver as a piston.

Surface X extrusion= Spl and this spl decreases with lower frequencies.

So the driver has to make more extrusion and have a lot of surface in a OB and often a equaliser.
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Old 10th October 2010, 08:22 AM   #15
Helmuth is offline Helmuth  Netherlands
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Here the simulation of the orion woofer. peerless xls10.

xmax 12,5mm sd=352 moved air max=440 cubic cm



http://www.selenium.com.br/site/asse..._pdfManual.pdf
The selenium xmax 3mm sd=860 moved air max=258 cubic cm


So it performs poorer to the xls 10 what maximum spl concerns within x-max of the motor.
But it perform better what low end cut off concerns due higher Q.

-3dB cut off xls10 = 60Hz

-3dB cut off selenium = 30Hz!!

The selenium is great but you shout use 3 drivers to compensate the limited xmax.
Attached Images
File Type: jpg orion.JPG (58.3 KB, 877 views)
File Type: jpg sele 3.JPG (58.2 KB, 1190 views)

Last edited by Helmuth; 10th October 2010 at 08:36 AM.
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Old 10th October 2010, 08:34 AM   #16
Helmuth is offline Helmuth  Netherlands
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Linkwitz has made a subwoofer thor to compensate the poor subbas of the orion.

XO sub/orion as aspected 50Hz

Click the image to open in full size.

Last edited by Helmuth; 10th October 2010 at 08:44 AM.
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Old 10th October 2010, 08:56 AM   #17
Helmuth is offline Helmuth  Netherlands
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Here the simulation of the bms woofer you selected.
Attached Images
File Type: jpg bms.JPG (45.3 KB, 843 views)
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Old 10th October 2010, 09:15 AM   #18
Helmuth is offline Helmuth  Netherlands
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The selenium will go down to 20Hz with some room gain so the hole audio spectrum is covered.

Click the image to open in full size.

Click the image to open in full size.

Last edited by Helmuth; 10th October 2010 at 09:25 AM.
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Old 10th October 2010, 10:45 AM   #19
DQ828 is offline DQ828  Australia
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Quote:
Originally Posted by Helmuth View Post
The selenium will go down to 20Hz with some room gain so the hole audio spectrum is covered.

Click the image to open in full size.

Click the image to open in full size.
Yes but unfortunately it is bigger than the 30cm I am trying to limit the woofer size to.
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Old 10th October 2010, 10:51 AM   #20
DQ828 is offline DQ828  Australia
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Default Hmmm

Quote:
Originally Posted by Helmuth View Post
Here the simulation of the bms woofer you selected.
Well that doesn't look to encouraging?

Thanks for the effort

David
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